Frost line depth in Avery County, NC
How deep the ground freezes in Avery County, NC
25 in. Dig to 26 in, just below the frost. Nearest NOAA station: Grandfather Mtn, 5.3 mi.
Your building department sets the legal frost line depth (IRC Table R301.2(1)); footings must go below it (R403.1.4.1). Call them before you dig.